<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			var a=prompt("请输入一个数字：");
			alert(isNaN(a));
			var i=parseInt(a);
			alert(i);
			alert(">>>>>>>>>>eval用法>>>>>>>>>>>>");
			var str="alert('胡军是个big帅哥')";
			eval(str);
		</script>
	</head>
	<body>
	</body>
</html>
